Water Quality Assessments of Selected Lakes Within ...SM 4500-P D 3 µg/L 28 days MEL Total Nitrogen epilimnion, hypolimnion H 2SO 4 to pH < 2 EPA 353.2 10 µg/L 28 days MEL Chlorophyll

Water Quality Assessmentsof Selected Lakes Within

Washington State

1999

July 2001

Publication No. 01-03-009

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Water Quality Assessments ofSelected Lakes Within

Washington State

1999

bySarah O’NealDave Hallock

Kirk Smith

Washington State Department of EcologyEnvironmental Assessment ProgramOlympia, Washington 98504-7710

July 2001

Publication No. 01-03-009

Page i

Table of Contents

Page

List of Tables ............................................................................................................................ ii

List of Individual Lake Assessments ....................................................................................... ii

Acknowledgments ................................................................................................................... iii

Abstract..................................................................................................................................... v

Introduction............................................................................................................................... 1Program Objectives........................................................................................................... 1

Methods .................................................................................................................................... 3Lake Selection................................................................................................................... 3Field Methods ................................................................................................................... 3Habitat Characterization ................................................................................................... 5Watershed Survey ............................................................................................................. 6User Perception Questionnaire ......................................................................................... 6Sample Analysis Methods ................................................................................................ 7Methods Used for Estimating Trophic Status .................................................................. 7Overall Lake Assessments and Setting Criteria ............................................................... 8

Quality Assurance and Quality Control Evaluation............................................................... 11Profile Data ..................................................................................................................... 12Laboratory Quality Assurance ........................................................................................ 13Field Quality Assurance.................................................................................................. 14

Summary................................................................................................................................. 17

Recommendations .................................................................................................................. 19

References............................................................................................................................... 21

Appendix A Glossary of TermsAppendix B Individual Lake AssessmentsAppendix C Quality Assurance/Quality Control Results for 1999Appendix D Hydrolab Quality Assurance/Quality Control Results for 1999

Page ii

List of Tables

Page

Table 1. Analytical methods used for samples collected for the LWQAProgram. ............................................................................................................ 4

Table 2. Median inter-annual standard deviations based on historical data as afunction of mean total phosphorus concentrations............................................ 9

Table 3. Summary of data quality objectives for the LWQA Program. ........................ 13

Table 4. Summary of Quality Assurance/Quality Control data for Hydrolabprofiles............................................................................................................. 14

Table 5. Summary of Quality Assurance/Quality Control Data for 1999. .................... 15

Table 6. Summary of individual lake assessments. ....................................................... 17

List of Individual Lake AssessmentsLake (County)

Big (Skagit)Browns (Pend Oreille)Campbell (Skagit)Curlew (Ferry)Deer (Stevens)Desire (King)Duck (Grays Harbor)Erie (Skagit)Gillette (Stevens)Harts (Pierce)

Long (Spokane)Loomis (Pacific)Martha (Snohomish)McMurray (Skagit)North Skookum (Pend Oreille)Potholes (Grant)Rowland (Klickitat)Sacajawea (Cowlitz)Starvation (Stevens)Terrel (Whatcom)

Page iii

Acknowledgments

The Lake Water Quality Assessment Program continued its new approach to lakeassessments in 1999 for the second, and final, year. This would not have been possiblewithout the support of management and the Washington State Department of Ecology(Ecology) 319 grant process. Funding for the program was supplied through anEnvironmental Protection Agency (EPA) 319 grant of $184,727. Unfortunately, this willbe the final year of the program due to a lack of continued funding.

A special thanks goes to:

◊ Michelle Ideker for formatting and preparing the manuscript for publishing.

◊ Jenifer Parsons for conducting the vast majority of the habitat surveys and supplyinginformation on aquatic vegetation.

◊ Maggie Bell-McKinnon, Rob Plotnikoff, and Bill Yake for reviewing the draft report.

Page iv

Page v

Abstract

Beginning in 1998, the Washington State Department of Ecology began a new approachto assessing lake water quality. Traditionally, lake monitoring focused on long-termtrends in water clarity and general lake assessments. Although trend data are crucial indocumenting declining or improving water quality, they provide very little information asto whether or not beneficial uses of a lake are impaired. The original intent of the CleanWater Act was to protect the beneficial uses (e.g., swimmable, drinkable, fishable) of ourwaters. This new approach is an attempt to evaluate the condition of the beneficial useson certain lakes throughout the state and to recommend lake-specific nutrient criteria forthose lakes in order to protect or restore their uses.

New methods were developed to evaluate variables on some of our monitored lakes. Monitoring concentrated on assessing fish and wildlife habitat, zooplankton, aquaticplants, watershed condition, water chemistry, and user perception. Beneficial uses weredetermined by evaluating the user perception surveys and talking with conservationdistrict representatives and the Washington State Department of Fish & Wildlife biologists. A lake-specific criterion was then recommended to protect or improveconditions on the lake. Lake-specific criteria were determined using procedures outlinedin general in Washington’s Water Quality Standards (WAC 173-201A) and in more detailherein. If proposed criteria are codified into the WAC, then, should a criterion ever beexceeded in a particular lake, measures could be taken either to reduce nutrientconcentrations or to conduct a more detailed study in order to refine the criterion.

Page vi

Introduction

In 1989, the Washington State Department of Ecology (Ecology) began a grant fundedstatewide lake monitoring program. Volunteers collected bi-monthly Secchi data (seeGlossary, Appendix A) and Ecology staff collected water quality data in the spring andlate summer. This program is described in Smith, et al., 2000. Our primary technicalgoal was to assess the trophic state (see Glossary, Appendix A) of as many lakes inWashington as possible.

We expanded the lake monitoring program in 1998 in response to the establishment ofnew water quality standards allowing the designation of lake-specific criteria and theavailability of additional funds. The lake monitoring program in 1998 and 1999 includeda lake-specific studies portion that expanded on the traditional basic assessment approach.(Our funding was reduced in 2000 to minimum levels needed to maintain the volunteerportion of the program. Our current primary technical objective is to assess long-termtransparency trends in 40 to 50 lakes statewide.)

The purpose of this report is to present the findings from the portion of the Lake WaterQuality Assessment Program (LWQA) that deals with lake-specific studies. In 1999, westudied 20 lakes. Lakes are reported and assessed on an individual basis (Appendix B); acomparative analysis of statewide lake water quality is not within the scope of this report.

Program Objectives

The objectives of the lake-specific studies portion of the program are as follows:

◊ Refine protocols for lake-specific studies established in 1998.

◊ Recommend nutrient criteria, if possible, for each studied lake as perWAC 173-201A-030(6) “Establishing lake nutrient criteria”.

◊ Pursue an integrated approach to lake assessment with Washington State Departmentof Fish & Wildlife (WDFW) officials, local government officials, and citizenvolunteers.

The specific goal for 1999 was to select and sample 20 lakes according to requests fromwithin Ecology, WDFW, and local governments.

Methods

Methods for lake selection, data collection, sample analysis, and data analysis aredescribed below. Methods for quality assurance and quality control (QA/QC) of datacollected for the program are discussed in the “QA/QC Evaluation and Results” section.

Lake Selection

Lakes were selected based on Water Quality Management Area needs assessment reports(e.g., Jacobson, 1996) and personal communications with Ecology regional officerepresentatives, WDFW biologists, and, in some cases, local governments. Variouscriteria were used in selecting lakes, such as a perception of water quality problems, othercomplementary on-going technical activities in the watershed, or simply a paucity ofknowledge about a particular popular or high-value lake.

Field Methods

Many of the field methods implemented in 1999 were adopted from methods used ordeveloped outside of Washington State, which were then customized for the Program’sneeds.

Sample Collection

Ecology staff visited lakes selected for special studies monthly from June throughSeptember. The purposes of these visits were to (1) collect Hydrolab profile data (seeGlossary, Appendix A) and sample for chemical parameters from the deep site of lakesonce each month; (2) conduct habitat assessments once during the season; (3) conductwatershed assessments in September; (4) collect zooplankton samples in June andAugust; (5) distribute user perception surveys; and (6) do Secchi depth quality assuranceevaluations with volunteer monitors on selected lakes.

During each field visit, the volunteer (on lakes with volunteers) escorted Ecologypersonnel to their monitoring site. The boat was anchored if possible. The volunteer andEcology staff each measured Secchi depth. Temperature, pH, dissolved oxygen, andconductivity profiles were completed using a Hydrolab Surveyor III and Reporter (seeGlossary, Appendix A). Temperature profile data were used to determine whether thelakes were stratified, and if so, to determine depths within the epilimnion andhypolimnion (see Glossary, Appendix A) for collecting water samples. Weatherconditions, water color, and general observations about the lake were recorded. If anobvious algal bloom was occurring at the surface or at depth (as indicated by a largechange in dissolved oxygen with no concurrent decrease in temperature), a sample wascollected for later identification. Macrophyte samples were either identified onsite orcollected for later identification. Algae and macrophyte samples were collected for

qualitative purposes only, and results may not include all species in the community. Complete aquatic plant surveys were conducted independently, and results of thosesurveys are also included (see Parsons, 1999).

During each visit, water samples for total phosphorous (TP), total persulfate nitrogen(TN), turbidity, and chlorophyll a were collected using a Kemmerer water sampler, andwere composited from two to three equidistant depths within the strata (epilimnion orhypolimnion) sampled (Table 1).

Table 1. Analytical methods used for samples collected for the LWQA Program.

Parameter Strata Sampled1SamplePreservation2

AnalyticalMethod3

MethodDetectionLimit Holding Time Lab4

TotalPhosphorus

epilimnion,hypolimnion

H2SO4to pH < 2

SM 4500-P D 3 µg/L 28 days MEL

Total Nitrogen epilimnion,hypolimnion

H2SO4to pH < 2

EPA 353.2 10 µg/L 28 days MEL

Chlorophyll a5 epilimnion MgCO36 SM 10100H(2,B)

0.5 µg/L 28 days MEL

Turbidity epilimnion SM 2540D, E 1 NTU 7 days MEL

Fecal ColiformBacteria

nearshore grabsamples (2sites)

SM 9222D 1 colony/100 mL

30 hours MEL

1 All samples except fecal coliform bacteria were composited.2 All samples kept on ice or stored at 4°C until delivery to the lab, or until filtered.3 Huntamer and Hyre, 19914 Manchester Environmental Laboratory (MEL)5 Corrected for phaeophytin.6 Approximately 2 mL saturated MgCO3 added with last of filtrate onto filter. Filters were iced, or frozen,

until delivered to lab.

Fecal coliform samples were collected approximately 20-35 feet from shore in areas thatwere suspected to have some potential source of bacteria. Fecal coliform bacteria samplebottles were filled by “scooping” water from about eight inches below the water surfaceto avoid surface films.

All samples, except those for chlorophyll a, were transported on ice to the lab and storedat 4°C. Chlorophyll a samples were filtered through Whatman 4.7 cm GF/C filters assoon as possible after collection. For most samples, 500 mL aliquots were filtered. About 2 mL of saturated MgCO3 was added to the last of the filtrate to preserve the

sample on the filter. Filters were placed in 10 ml of 90% acetone, then stored in the darkand on ice or refrigerated until transported to the lab for analysis.

Sampling Protocols for Zooplankton

A measure of uses on a given lake should include an evaluation of the health of a fishery.In a study of 18 natural lakes in upstate New York, Mills and Schavone (1982)demonstrated a strong correlation between mean length of cladocerans and planktivoreweight (r2 = .70; P

score was about midway between 2 (which indicates 20-30% vegetation) and 3 (whichindicates 40-75% vegetation). (The interpretation of the integer scores is provided in thesummarized report.)

Watershed Survey

A standard “windshield” survey of the watershed was implemented as part of the newapproach to assessing lakes because knowledge of the watershed may contribute tounderstanding attributes of the water quality in the lake. For instance, if agriculture ispredominant in the watershed, livestock or fertilizers may be impacting the lake’stributaries. Also, many poor management practices can be seen from the windshield of avehicle. This survey consisted of a thorough driving tour of the watershed. Observationswere recorded regarding land uses, management practices (good and bad), waterfowl, andbeneficial uses of the lake. Protocols and a copy of the survey form used in the field areincluded in Smith et al. (2000).

User Perception Questionnaire

The idea of implementing user perception surveys originated after reviewing researchconducted by University of Maine’s Water Research Institute. Maine’s researchdemonstrated relationships between water clarity, property values, and other socio-economic factors within the lake community (Boyle et al., 1997). WAC 173-201A-030(6) calls for public input before setting a nutrient criterion in a lake. The surveysconducted in Maine were modified and edited for Washington State then distributed tomost of the lake communities studied in 1999. The questionnaires were designed primarily to help investigators of lake water qualitydetermine the following:

1) Primary recreational uses and their relative importance.2) Lake user’s perception of the quality of those uses.3) Socio-economic value of the resource.

In 1999, however, efforts were focused primarily on objective #1 while objectives #2 and#3 were considered experimental.

The return of the questionnaires was voluntary, of course, and we did not follow up onnon-respondents. Although an effort was made to widely distribute the questionnaires,often only a small fraction was returned. Returns were greatest where volunteers wereavailable to distribute questionnaires by hand. For these reasons, we cannot applyconfidence intervals to the results. Therefore, questionnaire data are, essentially,considered “qualified” and results have been interpreted with caution. Nevertheless,questionnaire results complemented very nicely our own observations and often providedinsights that would otherwise have been missed.

Two types of questionnaires were developed, one for visitors and one for residents,though most questions were common to both. The resident questionnaire, followed by abrief synopsis of why each question was asked, is included in Smith et al. (2000).

Sample Analysis Methods

Methods used for sample analyses are listed in Table 1. Sample preservation andanalytical methods used by Manchester Environmental Laboratory (MEL) are describedin Huntamer and Hyre (1991).

Keys used for algal identifications were Smith (1950), Edmondson (1959), Prescott(1962; 1978), and VanLandingham (1982). Keys used for macrophyte identificationswere Tarver et al. (1978), Prescott (1980), and others (see Parsons, 1999).

Methods Used for Estimating Trophic Status

Carlson’s (1977) trophic state indices (TSI) for Secchi depth (TSISD), total phosphorus(TSITP), and chlorophyll a (TSICHL), tempered with professional judgment, were used toestimate the trophic status of the monitored lakes. In general, TSIs of 40 or less indicateoligotrophy, TSIs between 40 and 50 indicate mesotrophy, and TSIs greater than 50indicate eutrophy (Carlson, 1979). To describe lakes that appeared to be between trophicstates, the terms “oligo-mesotrophic” and “meso-eutrophic” were used. Refer to theGlossary in Appendix A for more detailed definitions of trophic state terms.

TSISD values were calculated from a time-weighted mean Secchi depth calculated fromall Secchi data collected between mid-May and mid-October 1999. A minimum of fiveSecchi depth measurements separated by at least two weeks were required to calculate anunqualified TSISD for each lake. TSISD values failing the five measurement minimum arequalified with the letter ‘N.’ TSITP and TSICHL values were similarly calculated fromtime-weighted mean total phosphorous and chlorophyll values, respectively.

It is not valid to average TSI values from different trophic state parameters, and to usethat average to summarize a lake’s trophic status. According to Carlson (1977), “the bestindicator of trophic status may vary from lake to lake and also seasonally, so the bestindex to use should be chosen on pragmatic grounds.” A subjective assessment of alldata collected during the monitoring season was used to determine an appropriate indexfor assigning trophic states. Other data collected during this study, data from othersources (short term lake surveys conducted by Ecology or universities, consultant reportsfrom Ecology-funded lake restoration activities, etc.), and information from thevolunteers (e.g. on aquatic herbicide use) were used to temper the trophic stateassessment for most lakes. As a result, the final trophic state estimations were not basedon TSI alone, and were not necessarily based on the same parameters for all lakes. Thebasis for each trophic state assessment is discussed in the “Summary” section of theindividual lake assessments in Appendix B.

Overall Lake Assessments and Setting Criteria

Water Quality Standards (WAC 173-201A (6)) suggest total phosphorus criteria for lakes(also referred to as “action values,” see Glossary, Appendix A) based on ecoregion andtrophic state. If measured concentrations are below the action value, a criterion may beproposed at or below the action value, or a lake-specific study may be conducted. Measured concentrations above the action value or where no action value is providedrequire a lake-specific study. The characteristics monitored in the LWQA Program aresimilar to examples included in the Water Quality Standards for lake-specific studies.

An evaluation of the primary beneficial uses on each lake is one of the purposes of thelake-specific study. These were determined from the user perception surveys,observations during sampling, and discussions with volunteer monitors. Determiningwhether or not the water quality in the lake supports the beneficial uses required bestprofessional judgment. The types of uses were considered and water quality wassubsequently determined sufficient or insufficient to support those uses. The results ofthe questionnaires were reviewed to determine how the users perceive water quality. Additionally, local governments, fish and wildlife officials, and other lake studies wereconsulted. Aquatic plant surveys as well as results from the habitat survey providedinformation on aquatic vegetation, which may impact the quality of swimming, fishing,and boating, as well as fish reproduction and wildlife habitat suitability.

If beneficial uses were supported, then the nutrient criterion recommended for the lakewas generally the mean total phosphorus concentration plus an adjustment for interannualvariation (described below), or the action value. In general, the more protective of eitherthe action value or the mean total phosphorous value was recommended as a criterion. The final recommendation also depended on best professional judgment as to whethercurrent nutrient concentrations were elevated due to anthropogenic sources.

If beneficial uses were not supported and were adversely impacted by artificially highnutrient concentrations, then further study may be necessary to determine what nutrientconcentrations will support the beneficial uses. Alternatively, if uses were not supportedbecause of habitat modifications, or other non-nutrient related attributes, thenrecommendations are made on how to improve conditions in order to support those uses. Recommendations can be based on the results from water quality, habitat, watershed, userperception, zooplankton, and Hydrolab surveys. One benefit of this new approach tolake assessment is the potential to integrate information for management purposes.

The lake-specific nutrient criteria proposed in this report were selected using informationcompiled through the seasonal sampling. As previously discussed, a criterion was usuallyrecommended as either the action value listed in the Water Quality Standards, or themean total phosphorus concentration plus an adjustment to allow for natural interannualvariation. This adjustment was calculated as the median interannual standard deviation ofall lakes monitored by the LWQA program for more than two years with similarphosphorus concentrations to the lake being evaluated (Table 2). For example, if the

seasonal mean value for phosphorus in a given lake is 18.3 ug/L, a recommendation of anutrient criterion of 18.3 + 4.1 = 22.4 ug/L total phosphorus was made. However, if thatlake was in the Puget Lowlands and was assessed as lower mesotrophic, the action valueof 20 ug/L may be recommended because the action value is more protective yet is stillabove the mean measured concentration.

Table 2. Median inter-annual standard deviations based on historical data as a function of mean total phosphorus concentrations.

Mean Phosphorus Concentration(µg/L)

Median Inter-annual StandardDeviation

Number of Lakes

Less than or equal to 10 3.0 19>10 through 20 4.1 43>20 through 30 5.1 17>30 through 40 8.0 16>40 through 60 15.0 7>60 through 80 27.8 2Greater than 100 70.6 8

The intent of recommended criteria is to be protective but not overly sensitive. The idealcriterion should be sensitive enough to have a reasonable probability of identifying lakesthat may be degraded or degrading; yet not so sensitive as to falsely identify lakes asdegrading that are merely undergoing inter-annual variation. Too insensitive a criterionwould fail to identify degrading lakes; too sensitive a criterion would falsely report toomany lakes as degrading and would be meaningless as a management tool. These criteriashould be considered preliminary. Once a lake has exceeded a criterion, a more detailedstudy should be conducted, including in particular a nutrient loading analysis, the firstobjective of which should be an evaluation and refinement of the criterion.

Quality Assurance andQuality Control Evaluation

All data collected for the LWQA Program were evaluated to determine whether dataquality objectives for the program (Table 3) were met. Methods used for data qualityevaluations are described in Lake Water Quality Assessment Program Quality AssuranceProject Plan (Hallock, 1995-draft). QA/QC analysis for all parameters is listed inAppendix C.

Table 3. Summary of data quality objectives for the LWQA Program.Parameter Detection

LimitPrecision Accuracy

(Bias)Secchi Depth -- < 10% CVa (daily pairs) <

5% CV (all pairs/lake)< 10% CVb(volunteer/ Ecology)

Total Phosphorus 5 µg/L < 7.5% CV (10 lab splits) < 2.5%relative bias(lab checkstandards)

Total PersulfateNitrogen

0.050 mg/L < 5% CV (lab splits) < 5%relative bias(lab checkstandards)

Chlorophyll a 0.5 µg/L < 10% CV (field dups)< 45% CV (May/August)

< 2.5%relative bias(lab checkstandards)

Profile parameters Temp. pH D.O. spec. cond.Fecal Coliforms

--------1 colony/100 mL

--------< 35% CV (lab splits)

± 1.0°C± 0.2 SU± 0.50 mg/L± 5 µmho/cm--

a Coefficient of Variationb In the case of Secchi depth, this isn’t truly “accuracy” but rather a comparison between volunteer and

Ecology staff collected readings. QC requirements for Secchi depth were only applied to volunteer-collected data.

Profile Data

The Hydrolabs were pre- and post-calibrated daily for pH and dissolved oxygen. The manufacturer’s instructions were followed for pH calibration, using pH 7 (low ionicstrength) and pH 10 (either low or standard ionic strength) standard buffer solutions. Post-calibration readings within 0.2 pH units of the buffer values were consideredacceptable. One post-calibration reading out of 90 taken did not meet quality assurancerequirements. All measurements failing quality assurance requirements are qualifiedaccordingly, as denoted by the qualifier “J,” indicating an estimate.

The dissolved oxygen sensor was calibrated against theoretical water-saturated air, inaccordance with manufacturer’s instructions. Daily field samples were collected forWinkler titrations and check standards. Post-calibration results within 0.5 mg/L wereconsidered acceptable. Eight post-calibration readings out of 45 taken failed qualityassurance requirements. Seven field checks of 15 taken failed quality assurancerequirements. (We have consistently had difficulties with oxygen check standards. Air calibration may be insufficiently accurate for our data quality objectives.) Allmeasurements failing quality assurance requirements are qualified accordingly, asdenoted by the qualifier “J,” indicating an estimate.

Specific conductance, a more stable parameter on the Hydrolab , was checkedperiodically using the manufacturer’s instructions. Potassium chloride standards used forconductivity calibration ranged from 101 to 147 µmhos/cm at 25°C (the molarity variedbetween individual solutions used). Post-calibration values within 5 µmhos/cm of thestandard value were considered acceptable. One post-calibration reading out of threecalibration checks taken did not meet quality assurance requirements. All measurementsfailing quality assurance requirements are qualified accordingly, as denoted by thequalifier “J,” indicating an estimate.

Temperature was also checked periodically against a National Bureau of Standards (NBS)mercury thermometer. Values within 1.0°C were considered acceptable. All four post-calibration results met quality assurance requirements. Post-calibration results are listedin Appendix D.

Additionally, two duplicate Hydrolab profiles were collected on each survey. “Nonsequential” duplicates were collected from the same station as the nutrient duplicatesample. “Sequential” duplicates were collected by retrieving the Hydrolab andimmediately repeating the measurements at the same station and depths as previouslymeasured. The precision of duplicate readings was calculated as the median of percentcoefficient of variation (CV%s) of data pairs from the same depths. Although no specificquality assurance standards were set for duplicate Hydrolab data, all median CV%s wereunder 4%, indicating good precision. Surprisingly, in general, nonsequential duplicatesdid not have greater variability than sequential duplicates indicating that one siteadequately represents whole lake conditions, at least for profile data. Median CV%s are

listed below in Table 4. Additionally, profile quality assurance results are listed inAppendix D.

Table 4. Summary of Quality Assurance/Quality Control data for Hydrolab profiles.DISSOLVEDOXYGEN

PH

NonsequentialDuplicates

Sequential Duplicates NonsequentialDuplicates

Sequential Duplicates

Date Median CV% Date Median CV% Date Median CV% Date Median CV%June 2.89 June 2.16 June 0.79 June 0.62July 1.53 July 2.53 July 0.16 July 0.65August 2.37 August 3.76 August 0.62 August 0.47September 2.24 September 3.09 September 1.17 September 1.01

TEMPERATURE CONDUCTIVITYNonsequentialDuplicates

Sequential Duplicates NonsequentialDuplicates

Sequential Duplicates

Date Median CV% Date Median CV% Date Median CV% Date Median CV%June 0.32 June 1.13 June 0.14 June 0.51July 0.19 July 0.89 July 0.19 July 0.87August 0.30 August 0.55 August 0.69 August 1.45September 0.09 September 0.64 September 0.20 September 0.57

Laboratory Quality Assurance

Laboratory QC requirements include the use of check standards, reference materials,matrix spikes, blanks, and lab split samples (duplicates). Lab splits are discussed below. For the most part, data quality for this project met all lab quality assurance and qualitycontrol criteria as determined and evaluated by the Manchester EnvironmentalLaboratory. Exceptions that caused results to be qualified as estimates include thefollowing: five turbidity samples exceeded holding times due to a shipping problem andsubsequent late arrival at the lab; one total persulfate nitrogen sample was qualified dueto improper storage in transit; two fecal coliform samples were qualified due to a colonycount greater than 150, indicating that results may be equal to or greater than the reportedvalue; and one fecal coliform sample was qualified due to the presence of motile, non-fecal spreader colonies which interfered with sample processing. Additionally, thirteenfecal coliform, four turbidity, three total phosphorous, and one total persulfate nitrogenresults were qualified as containing the analyte below the method’s limit of detection. These qualifiers were noted and taken into consideration when assessing lake waterquality and setting nutrient criteria.

Field Quality Assurance

Total Phosphorous Data

Lab precision was calculated by pooling the coefficients for all pairs of lab splits. Results(Appendix C) were all under the acceptable median CV% of 7.5 percent (Table 5).Total phosphorous samples were collected at a second site from ten lakes during thecourse of the survey. These duplicate samples were collected to evaluate therepresentativeness of collecting epilimnetic data from a single lake station. The QualityAssurance Project Plan (QAPP) for the LWQA Program (Hallock, 1995) states that thetotal precision of these nonsequential duplicates should be evaluated by pooling theCV%s for each pair and, if the median CV% exceeds 21 percent, then collecting from asingle lake station is generally not representative of lakewide epilimnetic phosphorous. Results (Appendix C) show that the median CV% did not exceed 21 percent; therefore,sampling at one site is generally representative (Table 5).

In addition to nonsequential duplicates, sequential duplicates were collected byimmediately repeating the sample collection at the original sampling site. Although nospecific quality assurance standards were set for sequential duplicate total phosphorousdata, all median CV%s indicate little variance (Table 5).

Other Water Chemistry Data

QA/QC evaluations for total nitrogen, chlorophyll a, solids, and fecal coliform bacteriafollowed the methods described in Hallock (1995). All available lab QC data results arelisted in Appendix C and summarized below in Table 6.

Total Nitrogen

All median CV%s for total nitrogen lab splits fell below the QAPP standard of 5 percent.Similarly, the nonsequential duplicate CV% in July (the only month measured) was wellunder the QAPP standard of 30 percent.

Chlorophyll a

All median CV%s for chlorophyll a lab splits fell below the QAPP standard of 10percent. Likewise, sequential duplicate results also fall at or below the QAPP standard of10%.

Fecal Coliform Bacteria

We did not conduct quality assurance calculations on fecal coliform data due to the widevariability in fecal concentrations expected in the field. A single fecal bacteria sample isnot considered to be representative lakewide. These samples were generally used to

assess high risk or potential source areas such as swimming beaches, heavily developedembayments, etc.

Turbidity

All paired turbidity readings were within 0.5 NTUs, the acceptable range set forth by theQAPP.

Table 5. Summary of Quality Assurance/Quality Control Data for 1999.TOTAL PHOSPHOROUSLab Splits (QAPP standard

Summary

Data collected for each lake, individual lake assessments, and proposed criteria aretabulated or discussed in Appendix B. We have recommended a phosphorus criterion forall of the 20 lakes monitored by this study (Table 6). Only one lake had TP concentrationsin 1999 that were greater than the proposed criterion (Deer Lake). If our proposed criteriaare approved, Deer Lake should become eligible for Total Maximum Daily Load studies.The other 19 lakes would not be in violation of water quality standards unless futurephosphorus concentrations exceeded criteria.

Table 6. Summary of individual lake assessments.Lake Name County Assessed Trophic

StateMean TP

Concentration(ug/L)

Proposed TPcriteria (ug/L)

Big Skagit Mesotrophic 18.7 20.0Browns Pend Oreille Oligo-mesotrophic 15.2 18.8Campbell Skagit Eutrophic 27.8 32.6Curlew Ferry Mesotrophic 19.3 20.0Deer Stevens Oligo-mesotrophic 21.4 20.0Desire King Meso-eutrophic 24.3 29.8Duck Grays Harbor Eutrophic 39.3 47.2Erie Skagit Eutrophic 28.8 33.7Gillette Stevens Mesotrophic 23.4 27.8Harts Pierce Eutrophic 67.3 87.0Long Spokane Mesotrophic 18.8 25.01

Loomis Pacific Eutrophic 40.6 48.6Martha Snohomish Mesotrophic 12.5 15.8McMurray Skagit Mesotrophic 21.5 25.8North Skookum Pend Oreille Eutrophic 23.2 35.9Potholes Grant Eutrophic 31.6 44.0Rowland Klickitat Eutrophic 39.9 51.4Sacajawea Cowlitz Eutrophic 76.6 101.2Starvation Stevens Eutrophic 68.4 90.0Terrel Whatcom Eutrophic 34.5 41.0

1 A criterion of 25ug/L total phosphorus from June 1 to October 31 in the eutrophic zone is already listed inthe Water Quality Standards (Chapter 173-201-080 (106) WAC).

Recommendations

◊ 1999 marks the final year of the LWQA Program due to a loss of EPA 319 grantfunding. While technical monitoring and lake assessments have been eliminated, wehave some funding to continue volunteer monitoring of Secchi depth for anotherseason. These data will be used to assess transparency trends. Lakes are a vitalecosystem, providing critical habitat as well as recreation. This lake monitoringprogram was the only statewide program that assessed the health of these ecosystems,and the only program that developed protective water quality criteria for lakes. Funding for lake monitoring should be restored.

◊ If the LWQA Program should obtain funding or be revived, several procedures needto be evaluated (see recommendations in Smith et al. 2000). Also, the accuracy of aircalibrating the profiling instrument oxygen sensor should be investigated.

References

Beaver, J.R., 1997. Zooplankton Workshop Reference Guide. North American LakeManagement Society 17th Annual International Symposium; December 3-6, 1997,Houston, TX.

Boyle, K., J. Schuetz, and J. Kahl, 1997. “Great Ponds Play an Integral Role in Maine’sEconomy.” Water Research Institute, University of Maine. Department ofResource Economics and Policy Staff Paper, REP 473, April, 1997, 50 pp.

Brett, M., and C. Goldman, 1996. “A Meta-analysis of the Freshwater Trophic Cascade.”Proceeding of the National Academy of Science, 93: 7723-7726.

Carlson, R.E., 1977. “A Trophic State Index for Lakes.” Limnol. Oceanogr.22: 361-369.

-----, 1979. “A Review of the Philosophy and Construction of Trophic State Indices” InMaloney, T.E. Lake and Reservoir Classification Systems. U.S. EnvironmentalProtection Agency Report No. EPA-600/3-79-074, pp. 1-52.

Edmondson, W.T. (ed.), 1959. Fresh-Water Biology, 2nd ed. John Wiley and Sons, Inc.,NY, 1248 pp.

Hallock, D., 1995 (in draft). Lake Water Quality Assessment Project Quality AssuranceProject Plan. Environmental Investigations and Laboratory Services Program,Washington Department of Ecology, Olympia, WA.

Huntamer, D., and J. Hyre, 1991. Manchester Environmental Laboratory, LaboratoryUser’s Manual, Third Edition. Washington State Department of Ecology,Environmental Investigations and Laboratory Services Program, Olympia, WA,342 pp.

Jacobson, J. A., 1996. Watershed Approach to Water Quality Management: NeedsAssessment for the Lower Snake Watershed. Water Quality Program, EasternRegional Office, Washington Department of Ecology, Spokane, WA.

Kaufmann, P., and T. Whittier, 1997. Surface Waters, Field Operations Manual forLakes, Section 5, Habitat Characterization. U.S. Environmental ProtectionAgency Report No. EPA/620/R-97/001.

Mills, E., and A. Schavone, 1982. “Evaluation of Fish Communities ThroughAssessment of Zooplankton Populations and Measures of Lake Productivity.” North American Journal of Fisheries Management 2: 14-27.

Parsons, J., 1999. Aquatic Plants Technical Assistance Program, 1998 Activity Report.Washington State Department of Ecology, Olympia, WA, Publication No. 99-328.

Prescott, G.W., 1962. Algae of the Western Great Lakes Area. Wm. C. Brown, Co.,Dubuque, IA, 977 pp.

-----, 1978. How to Know the Freshwater Algae. 3rd ed., Wm C. Brown Co., Dubuque,IA, 293 pp.

-----, 1980. How to know the aquatic plants. Wm. C. Brown Co. Publishers. Dubuque, IA.

Smith, G.S., 1950. The Freshwater Algae of the United States. 2nd ed. McGraw-HillBook Company, Inc., 719 pp.

Smith , K., D. Hallock, and S. O’Neal, 2000. Water Quality Assessment of SelectedLakes Within Washington State. Washington State Department of Ecology,Environmental Assessment Program, Olympia, WA, Publication No. 00-03-039.

Smith, K., J. Parsons, and D. Hallock, 2000. Water Quality Assessment of Selected LakesWithin Washington State: 1997. Washington State Department of Ecology,Environmental Assessment Program, Olympia, WA, Publication No. 00-03-009.

Tarver, D.P., J.A. Rodgers, M.J. Mahler, and R.L. Lazor, 1978. Aquatic and WetlandPlants of Florida. Florida Department of Natural Resources, 128 pp.

VanLandingham, S.L., 1982. Guide to the Identification, Environmental Requirementsand Pollution Tolerance of Freshwater Blue-Green Algae (Cyanophyta). Environmental Protection Agency EPA-600/3-82-073. 341 pp.

Appendix AGlossary of Terms

GlossaryAction Value – a total phosphorus (TP) value established at the upper limit of the trophic

states in each ecoregion. Exceedance of an action value indicates that a problemis suspected. A lake-specific study may be needed to confirm if a nutrientproblem exists.

Algae Bloom – abundant growth of algae that results in mats, scums, or otherwise densegrowths forming in or on the water. Not all types of algae form blooms.

Ambient Water Quality Monitoring – monitoring to collect baseline information on awater resource, which can therefore be used to determine if a water qualityproblem exists and how water quality is changing.

Bathymetric Map – a contour map of a lake’s depth.

Blue-Green Algae – a type of algae that, when found in bloom concentrations, is usuallyassociated with polluted or eutrophic water bodies. Most blue-green algae areconsidered to be nuisance species, because they may develop unpleasant scumsand odors.

Chlorophyll a – a pigment found in the cells of photosynthetic plants. The quantity ofchlorophyll a in a water sample indicates the amount of photosynthesizing algaeper volume of water. In this report, chlorophyll a concentrations are reported inµg/L.

Clean Water Act (Federal Clean Water Act) – this law requires water quality to bekept at an acceptable level to support both swimming and fishing in all surfacewaters. The authority to enforce this law is with the EPA, but this authority canbe delegated to individual states; it has been delegated to Washington.

Color – a test used to measure the color of water from which suspended matter has beenremoved. Color in water may result from natural metals, humus and peatmaterials, algae, and aquatic plants.

Conductivity – a measure of the ability of a solution to conduct electrical current. As ioncontent of water increases, conductivity will increase. The unit for expressingconductivity is µmhos/cm.

Cultural Eutrophication – eutrophication caused or accelerated by human activities.

CV – Coefficient of variation; calculated by dividing the standard deviation by the mean. It expresses variability relative to the mean of the sample.

Dissolved Oxygen – oxygen content in water that comes from being in contact with theatmosphere, from agitation (as in streams), or from being released byphotosynthesizing aquatic plants. Oxygen is depleted by bacteria that decomposevegetation or other organic material, and from respiration by plants and animals. The unit for expressing dissolved oxygen is mg/L.

Epilimnion – the “top” (closest to the surface), warmer layer of water in a thermallystratified lake. See metalimnion, hypolimnion.

Eutrophic – describes a lake that has high nutrient concentrations, abundant plant andalgae growth, and low water clarity. Eutrophication can occur naturally over time,or can be accelerated by human activities (see Cultural Eutrophication).

Fecal Coliform Bacteria – bacteria that are associated with mammal and bird feces. Fecal coliform bacteria results determine whether feces have entered andcontaminated a water body. Fecal coliform bacteria results are reported in thisreport in colonies/100 mL.

Hydrolab - the brand name of an instrument used to measure temperature, pH,dissolved oxygen and conductivity at various depths in water.

Hypereutrophic – describes a lake in advanced eutrophication which has very highnutrient concentrations, and very abundant plant and algae growth. In this report,hypereutrophic lakes will have a trophic state index value greater than 70.

Hypolimnion – when a lake is thermally stratified, the hypolimnion is the cooler layer ofwater at the bottom of the lake. See Epilimnion.

Lake Height – volunteers for this program measured the distance from a fixed point(usually on a stationary dock or piling) to the water surface. For most lakes thefixed point was above the water surface, so the greater the lake height value, thelower the water level.

Limnology – the science of lakes and streams, including the factors that influence thebiology and chemistry of inland waters. (From the Greek Limne, which means“lake”).

Littoral zone – The shallow area that extends from shore to the lakeward limit of rootedaquatic plants.

Macrophyte – any aquatic plant larger than algae that grows on, or in, water.

Meso-eutrophic – a trophic state that is borderline between mesotrophic and eutrophic.

Mesotrophic – describes a lake that has moderate concentrations of nutrients, a moderateamount of plant and algae growth, and moderate water clarity (generally 7 to 13feet, as measured with a Secchi disk).

Metalimnion – the middle layer of water between the epilimnion and hypolimnion of athermally stratified lake. The metalimnion is located at the thermocline.

mg/L – milligrams per liter. A unit used to describe the concentration of a substance insolution. One mg/L is equivalent to one part per million (ppm).

Nitrogen – an essential plant nutrient that can be present in water in various forms. Common forms are nitrate, nitrite, ammonia, and dissolved nitrogen gas. Nitrogen concentrations are reported in mg/L.

Nutrients – substances, especially nitrogen and phosphorus compounds, that fertilize thegrowth of aquatic plants and algae. The amount of nutrients in water will affectthe amount of plants and algae that can grow.

Oligotrophic – describes a lake that has low nutrient concentrations, little plant or algaegrowth, and very clear water.

Oligo-mesotrophic – a trophic state that is borderline between oligotrophic andmesotrophic.

Oxidation-Reduction Potential – “Redox” – the oxidizing or reducing intensity inwater, measured in volts. In chemical reactions, electrons flow betweenconstituents in a solution until equilibrium is reached; constituents which havegained electrons are reduced, and constituents which have lost electrons areoxidized.

pH – represents on a scale of 0 to 14 the acidity of a solution. A pH of 7 is neutral; acidsolutions such as vinegar have a pH of less than 7, and basic solutions have a pHgreater than 7.

Phase I Study – lake water quality monitoring (called a diagnostic/feasibility study)funded through the Centennial Clean Water Fund Program. Phase I must becompleted before Phase II (implementation of the lake restoration plan) can begin. For Phase I, twelve months of water quality data are collected and interpreted,and available restoration approaches are evaluated to determine the feasibility ofimplementing each approach.

Phosphorus – an important, often critical, plant nutrient that can be present in water invarious forms. Phosphorus can be dissolved in water (orthophosphorus),adsorbed onto particles, or taken up by plants. Phosphorus concentrations arereported in µg/L.

Phytoplankton – Microscopic plant plankton that live unattached in water.

Piscivore – an organism that habitually feeds on fish; in lakes, piscivores generallyinclude predator fish, birds, and freshwater mammals.

Planktivore – an organism that habitually feeds on plankton; in lakes, planktivoresgenerally include fish, waterfowl, and plankton.

Plankton – the assemblage of suspended minute plants and animals that have relativelylimited powers of locomotion, or that drift in the water subject to the action ofwaves and currents. Plankton forms the lowest level of the food chain, andincludes zooplankton and phytoplankton.

Productivity – the amount of algae, aquatic plants, fish, and wildlife a waterbody canproduce and sustain.

Profile Data – data collected at various depths of a lake to characterize a sampling sitefrom surface to bottom. In this report, profiled parameters are temperature, pH,dissolved oxygen, and conductivity.

Riparian – Pertaining to the banks of streams, lakes, or tidewater

Runoff – water that washes over a ground surface or within the soil column asgroundwater. Runoff can pick up suspended and dissolved substances from areasit has washed, and carry the substances to streams and lakes.

Secchi Disk – a black and white, 20 cm diameter disk that is attached to a rope. The diskis used to measure water transparency in open water. See Transparency.

Stratification (Thermal Stratification) – the state in which a lake forms distinct layers(the epilimnion and hypolimnion), usually because of the temperature differencesbetween the surface and bottom of the lake. These layers do not mix while thelake is completely stratified.

Thermocline – when measuring temperature from the surface to bottom of a lake, thethermocline is characterized by a considerable change in temperature with littlechange in depth. It is the transition area between the epilimnion and hypolimnion.

Total Suspended Solids – measures the amount of suspended matter that is filtered out of a sample of water, and dried at a specified temperature. Nonvolatile solids are the residue remaining after the sample is ignited at a specified temperature. The units for expressing solids results are mg/L. Suspended solids do not include dissolved solids (such as salts).

Transparency – generally, water clarity of open water measured by a Secchi disk iscalled Secchi disk transparency. Secchi disk transparency is a measurement of thedepth that sunlight can penetrate water and then reflect back up to the surface.

Trophic State – characterizes a lake according to the amount of plants that grow in alake. Trophic state also characterizes the water clarity and the amount of nutrientsin the water. See Oligotrophic, Mesotrophic, and Eutrophic.

Trophic State Index – a number that rates a lake according to the extent ofeutrophication. In this report, oligotrophic lakes have lower trophic state values,and eutrophic lakes have a higher trophic state index value.

Turbidity – a measurement of the effects of light-absorbing and light-scatteringsubstances that are suspended in water. Turbidity is determined by passing a lightthrough a sample and measuring the amount of light that is scattered by thesuspended particles. Turbidity is not the same as transparency.

Turnover (Lake Turnover) – the seasonal mixing of water layers that occurs whentemperature differences lessen between the top and bottom layers of water. Turnover occurs during fall in most lakes. Lakes that freeze over during winterwill also turnover after spring thaw.

Water Clarity – another term for Transparency.

Water Quality Standards – criteria established by Washington State for surface waters,cited in Chapter 173-201A WAC (Washington Administrative Code). Waterquality standards (for dissolved oxygen, pH, fecal coliform bacteria, temperature,and other parameters) are established for classes of rivers, streams, and marinewaters (Class A, AA, etc., depending on their characteristic uses), and lakes (LakeClass).

Watershed – all the area that collects water and drains to a lake via streams, surfacerunoff, or groundwater.

Winterkill – fish dill in lakes generally caused by the depletion of oxygen in water whilethe lake is frozen over.

Zooplankton – microscopic animals in water that eat algae and are eaten by fish.

µµµµg/Kg – micrograms per kilogram. A unit of concentration used to describe how manymicrograms of a chemical or contaminant are present in one kilogram of theanalyzed substance (such as sediment or fish tissue). One µg/Kg is equal to oneppb (parts per billion).

µµµµg/L – micrograms per liter. A unit of concentration used to describe how manymicrograms of a substance are in one liter of solution. One µg/L is equal to one

milligram per cubic meter (mg/m³), and to one part per billion (ppb). Onethousand µg/L is equal to one mg/L.

µµµµmhos/cm – micromhos per centimeter. A unit used to describe conductivity measuredby two electrodes 1 cm² in area and 1 cm apart.

Appendix BIndividual Lake Assessments

Lake ID: BIGSK1BIG SKAGIT

Big Lake is located five miles southeast from Mount Vernon and about twenty five miles south from Bellingham. It is fed by several inflows, the largest, Lake Creek, comes from McMurray Lake. Six additional unnamed tributaries are located along the western shore. It drains to the Skagit River via Nookachamps Creek. The lake is shallow with abundant plant and algal growth and is a popular water body for personal watercraft.

Area (acres)520

Maximum Depth (ft)23

Mean Depth (ft)14

Drainage (sq mi)22

Volume (ac-ft)7470

Shoreline (miles)6.21

Altitude (ft abv msl)81

Latitude48 23 52.

Longitude122 14 24.

CountyEcoregion: 2

Trophic State Assessment BIGfor 1999Analyst: Sarah O'Neal TSI_Secchi: 44

TSI_Phos: 46TSI_Chl: 50Narrative TSI: M

Big Lake is shallow, with abundant plant and algal growth. Despite its productivity, plants grew less densely than expected, and algal blooms were subtle enough to prevent detracting from the aesthetic value of the lake. The lake underwent Sonar treatment in the summer of 1998 to combat the invasive, non-native aquatic plants, Brazilian elodea (Egeria densa) and Eurasian watermilfoil (Myriophyllum spicatum). The treatment drastically reduced, if not eliminated, the milfoil and affected the Brazilian elodea, though not as significantly as hoped. A second sonar treatment was being considered for the summer of 2000. The lake experienced a steady decline in transparency through the summer, as indicated by Secchi readings. Shallow depths in the lake prevented thermal stratification, however, dissolved oxygen levels dropped off sharply near the bottom. We recorded one high fecal count in August near the public boat launch. The source of contamination is unknown. Possible sources include agriculture, stormwater runoff, goose and animal access, and swimmers. Popular activities on the lake included skiing and the use of personal watercraft. Most questionnaire respondents, however, were primarily interested in fishing. Survey respondents indicated a strong desire for restrictions on popular motorized activities. Visitors enjoyed warmwater fishing, particularly for largemouth bass. According to Washington Department of Fish and Wildlife (WDFW), yellow perch, largescale suckers, and brown bullhead were also abundant in the lake. Coldwater fish species declined dramatically since the last evaluation in 1978, although cutthroat trout and coho salmon utilized the lake at very low densities. A considerably lower percentage of large zooplankton in September than in June indicated heavy predation by planktivores. This suggests that population of piscivores may be too small to suppress planktivore density.

b

a

Station Information BIGSK1Station # 1Primary Station latitude: 48 23 15.9 longitude: 122 14 04.9Description: Deep part of lake. Directly north of boat launch, about 500 feet west of

shore.

BIG

Date TimeChloro-

phyll(ug/L)

Fecal Col.Bacteria

(#/100mL)Hardness

(mg/L)Tot N(mg/L)

Tot P(ug/L

Turbidity(NTU)

Strata Calcium(ug/L)

Chemistry Data

TN:TP

Station 06/9/1999 6 L

24 L

8/9/1999 45 L

270 JL

9/8/1999 3 L

1 UL

Station 16/9/1999 5 28.7 .363 16.1 .8 E 5850 23

7/15/1999 7.24 .305 14.1 1.2 E 22

.342 20.1 H 17

8/9/1999 4.1 .289 17.4 1.6 E 17

9/8/1999 11.7 .303 24.2 2.3 E 13

Strata: L=lake surface, E=epilimnion, H=hypolimnion; Qualifier: J=Estimate, U=Less than, G=Greater than.

Shallow depths, dense residential development, and a location in a relatively large watershed may render Big Lake particularly susceptible to (and may have already caused) human-caused eutrophication. In 1999, however, the water quality was supporting the lake’s primary uses, fishing and primary contact recreation. The mean measured total phosphorous concentration for Big Lake was 18.7. Pending a more thorough study, we recommend a tentative total phosphorus criterion of 20 ug/L, the action value for Puget Lowlands lower mesotrophic lakes. Future studies will likely recommend lowering this criterion.

Time-weighted means: Secchi = 3.1 m; TP = 18.7 ug/L; Chl = 7.6 ug/La TSI Qualifiers: B or W-Secchi Disk hit bottow or entered weeds; J-Estimate; N-Fewer than the required number of samplesb E=eutrophic, ME=mesoeutrophic, M=mesotrophic, OM=oligomesotrophic, O=oligotrophic

BIGSK1Secchi Depth and Profile Graphics Station: 1

5

10

15

20

25

02468Depth (m)

Tem

pera

ture

(C)

66.5

77.5

88.5

99.510

02468Depth (m)

pH (s

td. U

nits

)

0

20

40

60

80

100

120

0510Depth (m)

Cond

. (um

hos)

MayJunJulAugSep

02468

10121416

5/20/1

999

6/9/19

99

6/29/1

999

7/19/1

999

8/8/19

99

8/28/1

999

9/17/1

999

10/7/

1999

Date

Secc

hi D

epth

(ft)

0

2

4

6

8

10

02468Depth (m)

Oxy

gen

(mg/

L)

BIGSecchi Data and Field ObservationsDate Time Aesthetics

(1-bad, 5-good)

Boats- Fishing

(#)

Boats-Skiing

(#)

Bright-ness (pct)

Color(1-greens, 11-browns

Geese(#)

Rainfall(0-none, 5-heavy)

Secchi(ft)

Swimming(1-poor, 5-

good)

Temp-erature

(F)

Waterfowl(besides geese #)

Wind(1-none, 5-gusty)

Station 16/9/1999 5 1 50 2 0 15.09 4 0 1

Remarks: Slight algae bloom. Water very calm. Lots of large daphnia. Dissolved oxygen measurement qualified as an estimate due to calibration failing QA/QC requirements.

Sampler: SMITH

7/15/1999 4 1 1 50 6 27 9.02 4 19 3 Remarks: Sample site is directly east of white condo just 150 meters off east shore. Small algal bloom (blue-green). Water unusually

clear for July.Sampler: SMITH

8/9/1999 4 1 1 20 6 0 1 9.51 4 27 1 Remarks: Fec #1 at Big Lake Resort; Fec #2 at Public boat launch.Sampler: SMITH

9/8/1999 3 1 2 0 2 0 1 7.4 3 2 1 Remarks: Sample site right off Big Lake Resort. A considerable blue-green bloom. Fec #1 near north end of lake on west side near a

new dock approx. 300 yds from outlet.Sampler: SMITH

9/15/1999 7.22 Remarks:Sampler: Parsons

Lake ID: BROPE1BROWNS PEND OREILLE

Browns Lake is located twenty miles north of the Washington-Idaho border town of Newport. It sits in the Colville National Forest. It is fed by a small tributary in the Pend Oreille River drainage.

Area (acres)84


Mean Depth (ft)13

Drainage (sq mi)5

Volume (ac-ft)1085



Latitude48 26 12.

Longitude117 11 25.

CountyEcoregion: 8

Trophic State Assessment BROWNSfor 1999Analyst: Sarah O'Neal TSI_Secchi: 33 B

TSI_Phos: 43TSI_Chl: 33Narrative TSI: OM

Browns Lake was likely near its natural trophic state. Anthropogenic disturbance in the lake was limited to a US Forest Service campground and some logging in the watershed. No private development had occurred around the lake, and all motors were prohibited. Questionnaires indicated fly-fishing as the primary use. Questionnaire responses also indicated a desire to maintain the current motor restriction. WDFW stocked Browns Lake annually with approximately 20,000 cutthroat trout fry. The relatively cold and mostly oxygenated hypolimnion likely supported the trout. The lake's oligo-mesotrophic state clearly supported fly-fishing and other uses, including canoeing, kayaking, and relaxing. Average phosphorus concentrations were higher than would be expected given transparency and chlorophyll averages. A possible cause was the widely fluctuating water level in the lake which may have increased the proportion of sediment-associated phosphorus that was not biologically available. There was no evidence of internal phosphorus loading.

Because uses were supported and the trophic state of the lake was natural, a total phosphorus criterion may be set at the seasonal mean established during 1999 sampling, adjusted for interannual variability. Therefore, we recommend a total phosphorus criterion for the lake of 18.8 ug/L total (mean 15.2 ug/L plus standard deviation of 3.6 ug/L). However, nitrogen concentrations were very low and TN:TP ratios indicate nitrogen limitation. Because the lake may be nitrogen limited, if the application of nitrogen-based fertilizers is to be part of silviculture operations in the watershed, extreme care should be taken to stay well back from the lake, tributaries, and nearshore areas and timing and buffer requirements should be strictly followed. Other nitrogen sources should similarly be kept away from the lake.

Mean Secchi = 6.4m; Mean TP = 15.2 ug/L; Mean Chl = 1.3 ug/La TSI Qualifiers: B or W-Secchi Disk hit bottow or entered weeds; J-Estimate; N-Fewer than the required number of samples

b

a

b E=eutrophic, ME=mesoeutrophic, M=mesotrophic, OM=oligomesotrophic, O=oligotrophic

Station Information BROPE1Station # 1Primary Station latitude: 48 26 17.0 longitude: 117 11 46.0Description: Deep part of lake, mid lake out from USFS campground access.

BROWNS

Date TimeChloro-

phyll(ug/L)

Fecal Col.Bacteria

(#/100mL)Hardness

(mg/L)Tot N(mg/L)

Tot P(ug/L

Turbidity(NTU)


Chemistry Data

TN:TP

Station 16/15/1999 1130 .65 7.44 .083 17.7 .7 E 2020 5

.083 17.2 H 5

7/13/1999 1130 .54 .095 5.8 .6 E 16

.103 8.91 H 12

8/10/1999 1100 .8 .073 17.5 .5 UE 4

.107 15.9 H 7

9/14/1999 1040 2.6 .112 16.8 .5 UE 7


BROPE1Secchi Depth and Profile Graphics Station: 1

5

10

15

20

25

051015Depth (m)

Tem

pera

ture

(C)

66.5

77.5

88.5

99.510

051015Depth (m)

pH (s

td. U

nits

)

0

5

10

15

20

25

051015Depth (m)

Cond

. (um

hos)

MayJunJulAugSep

0

5

10

15

20

25

6/9/19

99

6/29/1

999

7/19/1

999

8/8/19

99

8/28/1

999

9/17/1

999

10/7/

1999

Date

Secc

hi D

epth

(ft)

02468

101214

051015Depth (m)

Oxy

gen

(mg/

L)

BROWNSSecchi Data and Field ObservationsDate Time Aesthetics

(1-bad, 5-good)

Boats- Fishing

(#)

Boats-Skiing

(#)

Bright-ness (pct)


Geese(#)


Secchi(ft)

Swimming(1-poor, 5-

good)

Temp-erature

(F)



Station 16/15/1999 5 4 0 0 2 0 1 20 5 0 3

Remarks: Bottom 11.0M. Water is clear and clean with some possible Volvox. Level is very high (5ft above base of a cottonwood near launch). No motors permitted. USFS campground only development. Two fishermen said they usually get RBT but cutthroat this year. Dissolved oxygen measurement qualified as an estimate due to calibration failing QA/QC requirements.

Sampler: HALLOCK

7/13/1999 5 4 0 0 3 0 1 21 5 0 2 Remarks: Sounds of logging in watershed. Water still high. Signs of crayfish. Dissolved oxygen measurement qualified as an estimate

due to calibration failing QA/QC requirements.Sampler: HALLOCK

8/10/1999 4 10 0 0 4 0 1 23.3 4 0 1 Remarks: Bottom 7.4M. Small Gloeotrichia-like specks. Lake level down several feet from last month. Plant fragments floating

throughout lake (Elodea and Ranunculus). Dissolved oxygen measurement qualified as an estimate due to calibration failing QA/QC requirements.

Sampler: HALLOCK


9/14/1999 4 1 0 0 2 0 1 20.7 B 4 6 2 Remarks: Bottom 6.1M. Secchi disk hit bottom. Elodea and Nitella came up on anchor. Water level ~15ft below high water mark on

trees. Lots of small (1.5cm) brown/black frogs. Gloeotrichia present. Not stratified.Sampler: HALLOCK

Lake ID: CAMSK1CAMPBELL SKAGIT

Campbell Lake is located four miles south from Anacortes, and approximately fifteen miles west from Mount Vernon. It is 1.5 miles long. It is fed by Lake Erie via a small stream and drains to Simlik Bay. Its macrophytes are mechanically harvested and it serves as a popular sport fishing lake.

Area (acres)367


Mean Depth (ft)8

Drainage (sq mi)6

Volume (ac-ft)2770



Latitude48 26 05.

Longitude122 36 53.

CountyEcoregion: 2

Trophic State Assessment CAMPBELLfor 1999Analyst: Sarah O'Neal TSI_Secchi: 53

TSI_Phos: 52TSI_Chl: 68Narrative TSI: E

Campbell Lake is probably naturally eutrophic. The lake is shallow, and had abundant plant and algal growth. High productivity prompted a restoration project for the lake in 1986, which included alum treatment. WDFW and Entranco Engineering documented a subsequent improvement in trophic state. However, two of three survey respondents indicated a decline in water quality (the remaining respondent did not know about water quality trends). This may have been due to both frequent--and occasionally foul smelling--algal blooms, as well as the introduction and proliferation of the invasive, non-native aquatic plant, Eurasian watermilfoil. The milfoil dominated the plant community in the lake and formed surface mats by mid-summer. The lake exhibited exceptionally high chlorophyll-a levels, which peaked in June with a concentration of 113 ug/L. This indicates an extraordinary level of photosynthetic activity. The lake shoreline was mainly vegetated, though it was significantly influenced by residential development. Residences dominated the watershed, but agriculture was also prominent, and cows were seen in the lake. How these potential sources of nutrients affected trophic state is unknown. Fortunately, fecal coliform levels remained insignificant throughout the summer, at least at designated sample sites.

Uses supported by the lake included swimming, fishing, and relaxing. Motorized activities included waterskiing and jetskiing, and questionnaire respondents consistently indicated a desire to restrict watercraft in order to reduce noise levels. A large littoral zone provided extensive warmwater fish habitat. The healthy zooplankton community decreased drastically in average size by August, indicating predation by planktivores and possible scarcity of piscivorous species. According to a WDFW survey, also conducted in 1999, largemouth bass and bluegill were the most abundant fish in the lake, followed closely by yellow perch. Brown bullhead, pumpkinseed, black crappie, and sculpin were also present at lower densities in Campbell Lake. No coldwater fish were found, however, likely due to warm temperatures and low oxygen levels at deeper depths.

Despite some indicators of poor water quality, uses of the lake appeared to be supported, including fishing, primary contact recreation, and relaxing. Because uses were supported, and the lake is probably naturally eutrophic, a total phosphorus criterion may be set at the seasonal mean that was established during 1999

b

a

Station Information CAMSK1Station # 1Primary Station latitude: 48 26 15.0 longitude: 122 37 00.0Description: About 50 meters off of the south side of the Island

CAMPBELL

Date TimeChloro-

phyll(ug/L)

Fecal Col.Bacteria

(#/100mL)Hardness

(mg/L)Tot N(mg/L)

Tot P(ug/L

Turbidity(NTU)


Chemistry Data

TN:TP

Station 06/8/1999 1 UL

1 UL

7/14/1999 1 L

1 L

8/10/1999 10 L

10 L

Station 16/8/1999 113 79 1.44 78.3 8.3 E 17200 18

7/14/1999 23.6 1.79 35.1 2.4 E 51

8/10/1999 15.4 .98 17.4 1.5 E 56

9/17/1999 15.7 .885 29.1 E 30


sampling, adjusted for interannual variability. Therefore, pending a more thorough study, including a nutrient budget analysis, we recommend a tentative total phosphorus criterion for the lake of 32.6 ug/L (mean 27.8 ug/L plus standard deviation of 4.8 ug/L).

Mean Secchi = 1.6m; Mean TP = 27.8 ug/L; Mean Chl = 44.0 ug/La TSI Qualifiers: B or W-Secchi Disk hit bottow or entered weeds; J-Estimate; N-Fewer than the required number of samplesb E=eutrophic, ME=mesoeutrophic, M=mesotrophic, OM=oligomesotrophic, O=oligotrophic

CAMSK1Secchi Depth and Profile Graphics Station: 1

5

10

15

20

25

0246Depth (m)

Tem

pera

ture

(C)

66.5

77.5

88.5

99.510

0246Depth (m)

pH (s

td. U

nits

)

210215220225230235240245250

0246Depth (m)

Cond

. (um

hos)

MayJunJulAugSep

0123456789

5/20/1

999

6/9/19

99

6/29/1

999

7/19/1

999

8/8/19

99

8/28/1

999

9/17/1

999

10/7/

1999

Date

Secc

hi D

epth

(ft)

02468

101214

0246Depth (m)

Oxy

gen

(mg/

L)

CAMPBELLSecchi Data and Field ObservationsDate Time Aesthetics

(1-bad, 5-good)

Boats- Fishing

(#)

Boats-Skiing

(#)

Bright-ness (pct)


Geese(#)


Secchi(ft)

Swimming(1-poor, 5-

good)

Temp-erature

(F)



Station 16/8/1999 4 2 0 0 3 0 1 2.46 1 1 2

Remarks: Eagle observed perching on Island. Very little algae at 4 meters. Oxygen plentiful down to bottom. A brilliant blue algae. Looks like Microcyctis--small spherical cells with no sheath. Lake heavily used by jet skis and water skiers.

Sampler: SMITH

7/14/1999 5 2 0 100 0 1 6.23 4 0 1 Remarks: Many many zooplanktonSampler: SMITH


8/10/1999 5 3 1 10 6 0 1 8.2 4 0 1 Remarks: A slight blue-green bloom.Sampler: SMITH

9/17/1999 5 1 0 10 3 0 1 5.6 2 0 1 Remarks: Significant algal bloomSampler: SMITH

Lake ID: CURFE1CURLEW FERRY

Curlew Lake is located 4.8 miles northeast of Republic. It is a natural lake, and water level fluctuations are stabilized by a three foot dam built in 1926. The lake extends northerly 4.8 miles to the outlet. There are four islands, totaling 20 acres, that are not included in the reported acreage. Inlets include Herron, Mires, Barrett, and Trout Creeks.

Area (acres)921


Mean Depth (ft)43

Drainage (sq mi)65

Volume (ac-ft)39519



Latitude48 46 03.

Longitude118 39 23.

CountyEcoregion: 8

Trophic State Assessment CURLEWfor 1999Analyst: Sarah O'Neal TSI_Secchi: 37

TSI_Phos: 47TSI_Chl: 41Narrative TSI: M

Curlew Lake is a large, deep lake with a steep shoreline. Its location in a sizeable watershed increases its susceptibility to anthropogenic eutrophication. In fact, practices throughout the watershed appear to have lead to a decline in the water quality of the lake. While clarity remained exceptionally high, excessive nutrients led to dense plant and algae growth which occasionally interfered with the lake's uses. Frequent algae blooms occurred throughout the summer. The relatively large body size of algae species may explain good transparency in spite of high chlorophyll and phosphorus levels. Plants grew densely, which is unusual in lakes with steep sides and a consequently reduced littoral zone. Dense macrophytes led to herbicide applications in 1988 and 1989 to control particularly weedy species. By 1999, however, those species again dominated the lake. Washington State University studied nutrient sources in Curlew Lake. The study implicated faulty septic tanks, livestock grazing in the watershed, fertilizer application, excessive plants, waterfowl, precipitation, groundwater, surface runoff, and past timber practices in the problem. Findings from the watershed survey agreed with these results. High total phosphorus levels in the hypolimnion also indicated internal loading, in which phosphorus is released from sediments into the water column. This often occurs when dissolved oxygen is absent near the lake bottom, as clearly indicated by the Hydrolab profile data. Anoxia also often leads to hydrogen sulfide near the bottom of the lake, causing an offensive, "rotten-egg" smell about which residents complained.

The lake supported a wide variety of uses. Survey respondents indicated fishing as the primary activity, with relaxing and canoeing/kayaking as other important interests. However, site visits to the lake and surveys also revealed water-skiing, swimming, picnicking, hunting, and bird watching as popular activities. Survey respondents indicated a desire for clearer water, as well as boat speed limits. Coldwater fish composed the majority of Curlew’s fishery. WDFW primarily managed the lake for rainbow trout. About 200,000 rainbow trout were released each year. Sixty-thousand of those were released annually from a cooperative net pen on the lake. Approximately 40% of tagged rainbow trout released from the net pen returned,

b

a

Station Information CURFE1Station # 1Primary Station latitude: 48 44 52.0 longitude: 118 39 48.0Description: Deep site: Center of basin north of Fisherman's Cove and Tiffany's

Resorts.

Station # 2Secondary Station latitude: 48 44 47.0 longitude: 118 40 05.0Description: Deep spot just north of the first island south of site 1.

CURLEW

Date TimeChloro-

phyll(ug/L)

Fecal Col.Bacteria

(#/100mL)Hardness

(mg/L)Tot N(mg/L)

Tot P(ug/L

Turbidity(NTU)


Chemistry Data

TN:TP

Station 16/17/1999 3.5 116 .35 23.7 .6 JE 32400 15

.535 116 H 5

7/15/1999 0900 1.93 .369 10.5 .8 E 35

.624 135 H 5

8/12/1999 0900 2.5 .392 16.3 .6 E 24

.634 190 H 3

9/16/1999 2.9 .358 22.2 .6 E 16

.691 228 H 3

Station 26/17/1999 3.7 .326 22.9 E 14

7/15/1999 1000 2.13 .375 13 E 29

8/12/1999 1015 2.5 .372 14.4 E 26

9/16/1999 3.1 .397 22 E 18


indicating an unusually good utilization of most fish. Trout prefer at least 4.5mg/L dissolved oxygen and water temperatures below 20 degrees Celsius, which limits their range in Curlew Lake to depths of six to sixteen feet during the summer. The dominance of smaller zooplankton suggested an ineffective amount of predators to suppress planktivore density. Tiger muskies were additionally stocked in the lake in an attempt to control an oversized northern pike minnow population. Known warmwater game species in the lake consisted only of largemouth bass.

While uses were supported for most of the year, there were two to three weeks annually during which quality was impaired enough to affect many lake activities. This generally resulted from particularly dense algae blooms. Consequently, we suggest implementation of appropriate best management practices throughout the watershed. We recommend a total phosphorus criterion of 20 ug/L, the action value for Northern Rockies lower mesotrophic lakes. This criterion will likely be exceeded during some years. Ferry County may want to consider adopting boat speed limits in certain areas or during certain times of day.

Mean Secchi = 4.9m; Mean TP = 19.3 ug/L; Mean Chl = 2.8 ug/La TSI Qualifiers: B or W-Secchi Disk hit bottow or entered weeds; J-Estimate; N-Fewer than the required number of samplesb E=eutrophic, ME=mesoeutrophic, M=mesotrophic, OM=oligomesotrophic, O=oligotrophic

CURFE1Secchi Depth and Profile Graphics Station: 1

5

10

15

20

25

010203040Depth (m)

Tem

pera

ture

(C)

66.5

77.5

88.5

99.510

010203040Depth (m)

pH (s

td. U

nits

)

210

220

230

240

250

260

270

02040Depth (m)

Cond

. (um

hos)

MayJunJulAugSep

02468

101214161820

4/30/1

999

5/20/1

999

6/9/19

99

6/29/1

999

7/19/1

999

8/8/19

99

8/28/1

999

9/17/1

999

10/7/

1999

Date

Secc

hi D

epth

(ft)

0

2

4

6

8

10

12

010203040Depth (m)

Oxy

gen

(mg/

L)

CURLEWSecchi Data and Field ObservationsDate Time Aesthetics

(1-bad, 5-good)

Boats- Fishing

(#)

Boats-Skiing

(#)

Bright-ness (pct)


Geese(#)


Secchi(ft)

Swimming(1-poor, 5-

good)

Temp-erature

(F)



Station 15/16/1999 5 7 0 100 2 25 5 16 5 39 3 2

Remarks: Used a view tube on the second Secchi reading but not on the first. Cloudburst and hail yesterday. Showers most of the week, sprinkling off and on today.

Sampler: PERRY

5/29/1999 4 7 0 0 6 4 1 16 4 44 8 1 Remarks: Used a view tube on the second Secchi reading but not the first. Lake has floating algae mats. Saw two live "Anadonta

californicus" clams today!Sampler: PERRY

6/13/1999 4 3 0 100 6 6 1 10 3 48 10 3 Remarks: Used a view tube on the second Secchi reading but not the first Secchi reading. Aesthetic enjoyment affected by floating

algae mats. Thermometer not functioning - fluid has separated. Distrust at least the last two readings.Sampler: PERRY

6/17/1999 3 7 5 6 15 1 14.5 2 68 5 1 Remarks:Sampler: PERRY

7/10/1999 4 12 0 0 6 0 1 14 3 69 5 Remarks: First Secchi reading taken without a view tube, second Secchi reading is with a view tube. Weed mats in shallows. Geese

feed here in afternoon - I sample in the morning.Sampler: PERRY

7/15/1999 4 8 2 60 6 2 1 17.4 4 20 2 Remarks: Bottom: 31.8M. P. crispus appears to be getting worse. Oxygen < 5 @ 8M, ~0 @ 25M. Some zoopl. and no H2S smell,

even at 25MSampler: HALLOCK

7/25/1999 4 2 0 50 6 0 2 15.75 4 68 2 1 Remarks: First Secchi reading without a view tube, second Secchi reading with view tube.Sampler: PERRY


8/8/1999 3 1 0 100 6 0 5 17.5 4 72 2 3 Remarks: First Secchi reading without a view tube, second Secchi reading with a view tube.Sampler: PERRY

8/12/1999 4 6 3 90 6 8 1 19 3 1 Remarks: Bottom: 34.5M. Algae specks clearly visible throughout water column. According to volunteer, there didn't used to be

nesting geese on the lake, but now are about 50 goslings/year and people are beginning to perceive them as a problem.Sampler: PERRY

8/22/1999 4 3 0 0 6 0 1 18 4 68 0 1 Remarks: First Secchi reading without a view tube, second Secchi reading with a view tube.Sampler: PERRY

Date Time Aesthetics(1-bad, 5-

good)

Boats- Fishing

(#)

Boats-Skiing

(#)

Bright-ness (pct)


Geese(#)


Secchi(ft)

Swimming(1-poor, 5-

good)

Temp-erature

(F)



9/5/1999 4 4 0 75 6 0 1 18.5 4 64 2 2 Remarks: First Secchi reading without a view tube, second Secchi reading is with a view tube.Sampler: PERRY

9/16/1999 2 6 50 3 12 1 16.4 2 30 1 Remarks: Bottom: 37.6M. Aphanizomenon bloom moderate to severe. Took zebra mussel veliger sample from state park pier.Sampler: PERRY

9/26/1999 4 5 0 50 6 4 1 16 4 60 11 1 Remarks: First Secchi reading taken without a view tube, second Secchi reading is taken with a view tube. Fewer clumps than last

time. Lake height taken one week later than rest of data. One brief rain shower in week. The Conductivity result is qualified as an estimate due to postcalibration failing QA/QC requirements.

Sampler: PERRY

Station 26/17/1999 14

Remarks:Sampler: PERRY

7/15/1999 35 6 1 17.1 2 Remarks: Bottom: 32.5M. Site 2 is just north of Dammann's (now Perry's) island.Sampler: HALLOCK

8/12/1999 6 20.34 Remarks: Bottom: 28.2MSampler: PERRY

9/16/1999 3 15.1 Remarks: Bottom: 32.2M.Sampler: PERRY

Lake ID: DEEST2DEER STEVENS

Deer Lake is located approximately 25 miles northwest of Spokane, just east of Highway 395.

Area (acres)1110


Mean Depth (ft)52

Drainage (sq mi)18

Volume (ac-ft)57000



Latitude48 06 28.

Longitude117 36 18.

CountyEcoregion: 8

Trophic State Assessment DEERfor 1999Analyst: Sarah O'Neal TSI_Secchi: 29

TSI_Phos: 48TSI_Chl: 32Narrative TSI: OM

Deer Lake is a large, deep lake which displayed many oligotrophic characteristics. Exceptional water clarity in the lake and low chlorophyll-a concentrations indicated little photosynthetic activity. Plants, mostly submerged, grew at moderate densities. No noxious weeds occur in the lake, though milfoil was present in nearby Loon Lake. Algal blooms occurred occasionally, but were not excessive. However, surprisingly high total phosphorus concentrations indicated a high mesotrophic state. Nitrogen limitation may explain why the mean Secchi depth and chlorophyll concentrations were lower than mean total phosphorus concentrations would indicate. Several potential nutrient sources existed in and around the lake. Approximately 600 homes, 450 of which were occupied year round, densely surround the shoreline. These homes were all on individual septic tanks until a sewer was built in 1992. Sparse vegetation around the shoreline resulted largely from development, with either buildings or lawns often extending up to the water's edge. This allowed runoff from the surrounding watershed to more easily enter the lake, including fertilizers used for lawn maintenance. Furthermore, cattle grazed up to and in the inlet to Deer Lake. Fencing cattle out of the lake, which occurred for the first time in 1999, may improve nutrient levels over time. Finally, logging occurred within the surrounding watershed. As well as high total phosphorus levels, one sample taken in August near the boat launch indicated a high fecal coliform concentration. The source of contamination is unknown, but possible sources include stormwater runoff, goose and animal access, and swimmers.

Questionnaire respondents indicated relaxing as their primary activity on the lake. Other uses included fishing, swimming, skiing, and boating. Questionnaire respondents indicated water quality, scenic views, fishing quality, and swimming opportunities added to the enjoyment of the lake and facilitated relaxing. WDFW managed the lake for eastern brook trout, rainbow trout, mackinaw (lake trout), and kokanee. They planted approximately 20,000 rainbow trout annually at a catchable size. Two-hundred-fifty-thousand small kokanee fry were planted between 1998 and 1999. Generally, kokanee exhibited little positive return. Kokanee that survived grew to a healthy size despite high mortality. In addition to the hatchery fish, there were

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a

Station Information DEEST2Station # 1Primary Station latitude: 48 06 25.0 longitude: 117 35 24.0Description: At the deep spot.

Station # 2Secondary Station latitude: longitude:Description: Near the end of the arm at the north end of the lake.

DEER

Date TimeChloro-

phyll(ug/L)

Fecal Col.Bacteria

(#/100mL)Hardness

(mg/L)Tot N(mg/L)

Tot P(ug/L

Turbidity(NTU)


Chemistry Data

TN:TP

Station 06/14/1999 1 UL

1 L

7/12/1999 1 UL

33 L

8/9/1999 5 L

160 L

9/13/1999 3 L

1 UL

Station 16/14/1999 .97 32.5 .25 23.5 .5 E 8920 11

.237 26.7 H 9

7/12/1999 1.71 .301 7.77 .5 E 39

.28 21.3 H 13

8/9/1999 1.1 .288 22.8 .6 E 13

two net pens on the lake. One contained rainbow trout and the other contained eastern brook trout. They each raised and released about 15,000 fish annually. Other species in the lake included yellow perch, sunfish, bullhead, large- and smallmouth bass, black crappie, and pumpkinseed. Zooplankton were exceptionally

Documents

Water Quality Assessments of Selected Lakes Within ...SM 4500-P D 3 µg/L 28 days MEL Total Nitrogen epilimnion, hypolimnion H 2SO 4 to pH < 2 EPA 353.2 10 µg/L 28 days MEL Chlorophyll